BACTERIOLOGICAL PROFILE OF ACUTE BACTERIAL MENINGITIS IN ADULTS IN A TERTIARY CARE HOSPITAL IN NORTH KERALA

CONTEXT Acute Bacterial Meningitis (ABM) is a medical emergency requiring immediate diagnosis and treatment. The bacterial pathogens responsible for ABM may vary with time, geographic distribution, age and preceding medical and/or surgical conditions of the patient. Information regarding the changing trends in terms of aetiology and antibiotic susceptibility in a particular region is essential for the correct and timely management of ABM. AIM This study was done to determine the bacterial pathogens responsible for ABM in adults and study their antibiotic susceptibility pattern. SETTINGS AND DESIGN A cross-sectional study was carried out on clinically suspected cases of ABM at Government Medical College, Kozhikode, for a period of one year. METHODS AND MATERIALS Samples of Cerebrospinal Fluid (CSF) collected aseptically from clinically suspected cases of ABM were centrifuged and subjected to culture, Gram staining and antigen detection by Latex Agglutination Test (LAT). Antibiotic susceptibility testing was performed on all the isolates. Cases of post-traumatic meningitis and meningitis developing after neurosurgical procedures were also included in the study. RESULTS CSF samples were collected from 165 clinically suspected cases of ABM and processed. The bacterial pathogen could be identified by centrifuged Gram stain in 21 cases (12.7%), by culture in 16 cases (9.7%) and by LAT in nine cases (5.4%). Streptococcus pneumoniae was the predominant pathogen isolated in 7 cases (43.8%) followed by Pseudomonas aeruginosa in 4 cases (25%), Acinetobacter baumannii and Coagulase negative staphylococci (CoNS) in two cases each (12.5%) and Staphylococcus aureus in one case (6.25%). Drug resistance was common among Gram negative isolates in three cases (50%). CONCLUSION Streptococcus pneumoniae remains the most common aetiological agent of ABM in adults. Multidrug resistant Gram negative bacilli are also important emerging causes of ABM. This study shows the importance of centrifuged CSF Gram smear along with culture for the accurate diagnosis of ABM in developing countries. LAT can be used as a simple, rapid and convenient test to establish the bacterial aetiology in ABM.